冻融作用对植被混凝土抗剪强度的影响

Effect of freeze-thaw action on vegetation-growing concrete shear strength

为探讨冻融作用对植被混凝土生态基材抗剪强度的影响,选取冷端温度、含水率和融化温度为影响因素,采用快剪试验监测原始样与冻融样的黏聚力和内摩擦角。结果表明:1)经历冻胀与融沉过程后,植被混凝土的黏聚力降低,内摩擦角在多数情况下表现为增大,二者的耦合作用显示抗剪强度有所降低;2)随着冷端温度的降低,植被混凝土冻融后的黏聚力逐渐减小,而内摩擦角却逐渐增大;3)含水率对植被混凝土黏聚力与内摩擦角的影响具有双重效应,随着含水率的增大,植被混凝土冻融后的黏聚力先快速减小而后缓慢减小至稳定值,而内摩擦角却逐渐减小;4)融化温度的改变不会造成黏聚力和内摩擦角的变化,仅影响冻结植被混凝土的融沉历时。

In order to explore the effect of freeze-thaw action on the shear strength of vegetation-growing concrete, we took cold-end temperature, water content and thawing temperature as influencing factors to monitor cohesives and internal friction angles of initial and frost-thaw samples by quick shear test. The results showed that after a process of frost-heave and thaw-settlement, vegetation-growing concrete cohesive reduced, but its internal friction angle increased in most cases. The coupling effect of cohesive and internal friction angle indicated that vegetation-growing concrete shear strength decreased. As the cold-end temperature dropped, vegetation-growing concrete cohesive decreased and its internal friction angle increased gradually after the process of frost-thaw. The moisture content had a dual effect on the cohesive and internal friction angle of vegetation-growing concrete. With the increase of moisture content, the cohesive decreased rapidly at first and then decreased slowly to a stable value finally, but the internal friction angle kept declining all the time. The change of thawing temperature had no effects on the changes of cohesive and internal friction angle except on the thaw-settlement time of vegetation-growing concrete.